Cyber jihadists dabble in DDoS: Assessing the threat

DDoS attacks that occurred previously provide visibility into these actors’ targeting strategies, limitations, and capabilities — all of which can help us assess the scope and credibility of the risks they represent.

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Recent events suggest that while cyber jihadists appear to remain of low skill and under-sophisticated, their toolset is expanding. Between December 2016 and January 2017, two distinct pro-ISIS cyber threat groups experimented with distributed denial of service (DDoS) attacks and achieved limited apparent successes. Although the attacks have since ceased, these actors have expressed interest in engaging in similar and potentially more offensive cyber activities in the future. Indeed, the DDoS attacks that occurred previously provide visibility into these actors’ targeting strategies, limitations, and capabilities — all of which can help us assess the scope and credibility of the risks they represent.

Background

In December 2016, when one member of a top-tier ISIS Deep Web forum first discussed the possibility of DDoS, the initiative quickly gained support. Five weeks later, after the group’s ringleader finished developing a proprietary DDoS tool dubbed “Caliphate Cannon,” the group launched its first DDoS attack. As recently as late May 2017, the tool’s author referenced a new version in development, suggesting that more attacks may follow.

Around the same time, another pro-ISIS group known as the United Cyber Caliphate (UCC) also claimed credit for DDoS attacks. Although UCC did not provide any details regarding their attack methodology, the group likely used a booter/stresser — also known as a “DDoS-for-hire” service. Some of this activity was captured by a “honeypot” — a tool that monitors attack traffic from these types of services — which logged attacks against at least two of the targeted sites, the details of which corresponded to UCC’s claims.

Targeting strategy

Although the UCC attacks were not accompanied by a discussion of targeting strategy or priorities, the forum community's attacks using Caliphate Cannon were. The effort's ringleader prioritised military and economic targets as well as security and education networks. While news agencies and even satellites were also considered desirable, the forum members recognised that such targets would likely be too difficult given their capabilities and resources.

The organiser of the DDoS efforts also published a survey to solicit feedback from forum members with regard to geopolitical priorities. The survey offered four categories: Crusader (the US-led anti-ISIS coalition), Iraqi government, Syrian government, and "Tyrants" — a term often used to describe Middle Eastern governments. Upon the close of the survey, the "Tyrants" category had obtained the most votes, followed by "Crusader."

Based upon those results, the forum community launched DDoS attacks against government targets in Egypt, Jordan, Yemen, and Iraq, with the latter receiving multiple attacks. No evidence suggests collusion between the forum community and UCC; however, six of the seven websites UCC claimed to have attacked were government, NGO, or private businesses' websites in Iraq.

Results of the attacks

UCC claimed credit for seven DDoS attacks in December 2016; the forum community targeted five sites throughout the second half of January 2017. Although at least one site targeted by UCC was confirmed offline after the attack was announced, Flashpoint analysts cannot confirm the site was online prior to the attack. The forum community’s organiser posted reports after each attack, most of which lasted three or more days. Each report included claims that the sites had gone down intermittently or suffered degraded response times.

Additionally, Flashpoint analysts cannot confirm that the sites targeted by Caliphate Cannon were offline due to the DDoS activity; however, the evidence is compelling. At least two of the sites were confirmed offline when analysts attempted to check their availability. Of those sites, one was hosted on a web server in Yemen and the other in Iraq. In the first case, the entire server appeared to have been affected, denying access to 260+ of its hosted sites. In the second case, the site was offline for nearly two months before returning on a new IP address hosted by a DDoS protection service.

Potential capability

Without better insight into the infrastructure on which the target sites were hosted, we can make some inferences from the tool used and the potential size of the population of attackers. Caliphate Cannon was designed to carry out HTTP flood attacks by sending a deluge of HTTP GET requests to the target site. Because flood attacks are volumetric, they also rely on either one or more machines with the capacity to generate large volumes of traffic, or a large enough population of attacking devices to generate that traffic.

Despite the apparent success at knocking some sites offline, it is unlikely that the attack population was large enough to generate the volume of traffic necessary to realise success against targets with DDoS mitigation strategies. Unfortunately the tool’s download pages remain inactive, so it is impossible to view the number downloads. However, one means of estimating the population of attackers is to look at the number of active users on the forum during the period of the attacks.

Since the forum is password-protected, the links were only available to those with login credentials. Of those, it is impossible to speculate the number of users who might simply have browsed the forum; however, it is possible to formulate a picture of active users by looking at the number of users who posted to the forum after the download links were posted. Between January 12, 2017, when the tool was first posted, and January 31, 2017, when the last targeted site went offline, there were 282 unique users who posted in the forum.

These observations raise a crucial question: If all 282 users were to download the tool and participate in the attacks, would they generate enough traffic to have an impact on higher-value targets, most of which likely employ DDoS mitigation strategies? Theoretically, yes. Under ideal conditions, 282 attackers could generate enough collective traffic to impact such a site.

However, these actors face several limiting factors. First, many are believed to be in the Middle East and North Africa region, where Internet infrastructure is less developed and network speeds limited.

Second, these actors face complex security concerns that go beyond potentially committing computer crimes under the law in their respective countries; they are also supporting a terrorist organisation. This reality drives many of these actors to use the Tor network to obfuscate their Internet activity. Caliphate Cannon sends attack traffic over Tor by default, which further slows connection speeds and attack traffic potential — an obstacle that would even impact actors in countries with more developed Internet infrastructure.

Finally, Caliphate Cannon employs no mechanism to coordinate the timing of attacks. This leaves the potential for a fractured attack population to send traffic at different times, further limiting the cumulative volume of attack traffic at any given time.

What if the attacks resume?

Without significant advancements in technical capabilities, these jihadist cyber threat actors have a couple of options should they decide to resume DDoS attacks. As was likely the case during UCC’s attacks, the first and easiest method is to pay for booter services. Funding, however, could be a limiting factor. These groups are not officially recognised by ISIS, and no evidence suggests that their activities are directed by ISIS commanders. Without an operations fund, even cheap services may not be sustainable.

Another option is to grow the attack population. The author of Caliphate Cannon discussed releasing a second copy of the tool, devoid of any ISIS symbols, in order to achieve exactly that. In one post, the actor claimed that removing ISIS symbols could help the group co-opt others — likely hacktivists — into the attacks while concealing the initiative’s jihadist ties. Although this tactic could work, the hacktivist community is fractious; coordinating a large enough group to generate ample traffic is unlikely.

Lessons learned

Ultimately, cyber jihadists’ DDoS experimentation teaches us two lessons. First, these actors are resourceful and innovative. Although most lack advanced technical skillsets, they continually search for ways to overcome their limitations and approach problems in interesting ways. Second, these actors derive value even from perceived successes. ISIS has proven particularly adept at leveraging the digital realm as a platform for propaganda and recruitment. Activities conducted in the name of ISIS contribute to this machine; and in the propaganda war, perception is reality. With even a fraction of truth, these actors can spin issues in their favour while denouncing factual refutations as enemy propaganda.

In the end, if these actors do resume DDoS attacks, any successes will likely align with the scope of their successes in other activities. Website defacements, for example, often occur when these actors exploit known vulnerabilities typically found in low-value targets. In other words, soft targets. If the impact of a DDoS attack is measured in terms of loss or degradation of service — such that it drives customers away from a given site — these actors are unlikely to realise success against hardened targets. However, even perceived successes are likely to embolden and motivate these actors to continue seeking the means to achieve a greater impact.